(1) If seen as mindless automata, insects may symbolize either (your attitude towards) your instinctive drives or unconscious
forces that seem to constitute a threat to the rule of reason. In either case, you probably need to overcome - or at least examine - your replusion.

(2) If it is a solitary insect, it may be bringing a message from your inner self. That your inner self should appear in such a paradoxical guise or employ such
a dispicable and unlikely ambassador is a reflection of your (very unwise) contempt for your inner self, as shown perhaps in the way you exclude it from your conscious life.
(Remember the cricket in Pinocchio's adventures?)

Spider

A spider is a common symbol of mother as an object of fear or dislike and particularily in a man's dream. Freud sees it as a symbol of 'the phallic mother (big surprise), of whom we are afraid; so that the fear of spiders expresses
dread of mother-incest and horror of the female genitals' (Freud's own italics). Try to get to know, not only your mother, but - more important - what your mother means to you. One way of doing this is to converse with the spider: hold it in your mind and ask it searching questions.